Fig. 1

Severe bileaflet mitral valve prolapse in a patient with Marfan syndrome. Top row: diastolic frames in 4-, 2- and 3-chamber orientations. Mid row: corresponding systolic frames. Bottom row: on each systolic view, the prolapsed area is measured by planimetry (green area). This area is divided by the mitral annular diameter (red line) to calculate the prolapsed height. The average of the three calculated prolapsed heights gives the mean prolapsed height of the mitral valve